A source tells the paper de Blasio was in Brooklyn and not City Hall because he was making fund-raising calls for his re-election from a restaurant or coffee shop in Park Slope. The de Blasio family maintains a home in the neighborhood. The mayor routinely works out in a local gym there and returns to Gracie Mansion in Manhattan.

When asked about the use of a helicopter to travel a relatively short distance and not opting for mass transit instead, the Mayor's office referred questions to the NYPD.

"The security and transportation of the mayor are determined by the NYPD. We do not discuss the specifics of security," said Deputy Commissioner John Miller.